Feeding device for sheet material



NOV. 24, 1953 1 HALLER FEEDING DEVICE FOR SHEET MATERIAL 5 Sheets-Sheet l Filed June 26, 1948 Nov. 24, 1953 3 Sheets-Sheet 2 Filed June 26, 1948 Brwentor Je f/f l Ctttornegs Nov. 24, 1953 J. HAL-LER EEEDING DEVICE EoR SHEET MATERIAL 3 sheetsus'heet 5 Filed June 26, 1948 Patented Nov. 24, 1953 UNITED STATES PATENT OFFICE 7 Claims.

This invention'relates to feeding devices for feeding sheet material such as sheet steel, to machines utilizing such material, such as punching, stamping or shearing machines.

One object of this invention is to provide a feeding device for sheet material wherein the sheet may be moved unusually large distances between successive operations of the machine being fed, such as in the production of unusually large stampings by a punch press.

Another object is to provide a feeding device for sheet material wherein the sheet material is fed by feeding rolls which are rotated a predetermined circumferential distance to advance the sheet material a similar distance between successive operations of the machine being served, thereby avoiding the diiculties arising in the provision of reciprocating feeding devices for large stampings or the like requiring long distances for the material to be moved between operations of the machine being served.

Another object is to provide a feeding device for sheet material of the foregoing character containing devices for disengaging feeding rolls from gripping engagement with the sheet material at the end of the feeding stroke in order to permit the sheet material to move slightly so as to adjust its position with extreme accuracy by means of a pilot pin on the machine being served entering a pilot hole in the sheet material.

Another object is to provide a feeding device for sheet material of the foregoing character wherein a constant drive is maintained on all sets of rolls regardless of their separation, the rolls on opposite sides of the sheet material being positively driven Another object is to provide a feeding device for sheet material wherein the actuation of the feeding mechanism is brought about by servomechanism operated in response to the motion of a part of the machine being served, such as the motion of the platen of a punch press.

Another object is to provide a feeding device for sheet material of the foregoing character, wherein the rolls which feed the sheet material are required to rotate in one direction only, thereby avoiding the shock and vibration of reversing the rotation of mechanisms where large sheets of material are to be handled in order to produce workpieces of unusually large size.

ln the drawings:

Figure l is a side elevation, partly in section, of a feeding device for sheet material, according to a preferred form of the invention, as attached to and controlled by a stamping press;

Figure 2 is a top plan view, partly in section, of the feeding device shown in Figure 1;

Figure 3 is a vertical cross-section taken along the line 3 3 in Figure l, showing the feeding roll operating mechanism;

Figure 4 is a vertical longitudinal section taken along the line 4 4 in Figure 3, showing the mechanism for manually raising and lowering the feeding rolls;

Figure 5 is an enlarged fragmentary end elevation of the braking mechanism for preventing overriding of the feeding4 rolls, looking in the direction of the line 5-5 in Figure 3; and

Figure 6 is a cross-section through the unidirectional roll driving clutch, taken along the line 6-6 in Figure 3.

Referring to the drawings in detail, Figure 1 shows a sheet metal working machine, generally designated ID, such as a stamping press, arranged to be served by a sheet material feeding device generally designated II according to a preferred form of the invention. Thel sheet metal working machine II] may be of any type, the stamp-ing press shown being chosen for purposes of illustration and not by way of limitation. The machine I which is served by the feeding device II is shown diagrammatically as consisting of a bed I2 to which are connected (by means not shown) vertical guide members I 3 and I4 in which a platen I5 reciprocates vertically.

Mounted on the platen I5 is a punch unit I6 which is aligned with and cooperates with av corresponding die unit I1 mounted on the bed I2.

` The punch unit I6 is shown, for purposes of illustration, as having a pair of punches I8 and I9 cooperating with a pair of cavities 20 and 2l respectively in the die unit Il. The punch unit I6 also carries a tapered pilot pin 22 which is adapted to enter a pilot pin cavity 23 in the die unit I1. The pilot pin 22 is for the purpose of entering a pre-formed locating hole or pilot hole 24 in the sheet material S which is to be worked. The punches I=8 and I 9 subsequently produce the holes 25 and 26 in the sheet material S when they descend and enter the cavities 2t and 2l in the die unit I'I. The pilot pin or locating pin 22 serves to move the sheet material S' slightly after it has been fed by the feeding device II in order that the holes 25 and 26 shall be precisely located relatively to the position of the pilot hole 24.

Secured as at 21 to the platen I5 and movable therewith are two vertically spaced L.shaped brackets 28, to the vertical arms of which are adJustably secured cam plates 29 having upper and lower cam slots 30 and 3l respectively. The

cam slots 30 and 3l have parallel ends with inclined central portions and engage follower rollers 32 upon the ends of pistons 33 reciprocable in upper and lower hydraulic cylinders 3d and 35 respectively. The cylinders 34 and 35 are of similar construction and are similarly supported on the guide member or press frame I4 by brackets 36 bolted thereto. The cylinders 34 are provided with reservoirs 3l for oil or other suitable fluid communicating with the cylinder bores 38 through ports 39, 40 and M. The ports 39 open directly into the cylinder bore 38 whereas the ports di) open into check valve chambers 42 from which the ported! open into the cylinder bores 3S. The check valve chambers d2 at their lower ends are provided with valve seats i3 engaged by ball relief valve members d'4 urged downward by coil springs 45 seated against screw plugs i6 threaded into the upper end of thevalve chambers 42.

The upper and lower cylinders 34 and 35 are provided with fluid ports 41 and 48 respectively connected to pipes :9 and 5t leading to certain portions of the feeding device Il as explained below. Meanwhile, it may be stated that the pipe 49 supplies pressure fluid to actuate a servomotor 5l which operates a control valve 52. The latter, in turn, controls the flow of fluid to a hydraulic motor which operates the feeding rolls. The pipe 50, on the other hand, supplies pressure fluid to hydraulic motors which raise the upper feeding rolls from disengagement with the sheet material S at the end of a feeding stroke, so as to free the sheet material to be capable of moving slightly for re-alignment purposes when the Feed roll operating 'mechanism The servo-motor el is bolted as at 53 to the base or bed 54 of the feeding device il and contains a cylinder 55 with a piston 56 reciprocable therein and urged to the right by a coil spring 5l, the tension of which may be adjusted by an adjusting screw 58. The piston rod 59 of the servo-motor 5| is connected to the valve rod @El of the control valve 52. Consequently, the pressure fluid entering through the pipe i9 serves to shift the valve rod 6i) and valve spool 6i to the left, whereas the spring 5l shifts it to the right into the position shown in Figure l when iiuid is withdrawn from the pipe 49. The control valve 52 is a conventional four-way valve of a type well-known to hydraulic engineers and hence requires only a superficial description. The three-headed hollow valve spool Si reciprocates in a valve bore $2 which is provided with spaced ports to which are connected a central pressure fluid supply pipe t3, pressure fluid service pipes 64' and t5 on opposite sides thereof', and a pressure fluid discharge pipe 66. The control valve 52 is bolted as at 61 to the bed 54'. The pipe 63 is connected to a suitable pump (not shown) and the pipe 86 to a fluid reservoir connected to the pump.

Bolted as at E8 to the bed 54 is a hydraulic motor generally designated Se of the variable stroke piston and cylinder type having a cylinder 'l0 tothe opposite ends of -which the pressure Cil fluid service pipes 84 and S5 lead. Reciprocably mounted in the cylinder bore 7! of the cylinder 70 is an adjustable stroke compound piston 'l2 having a movable head 'i3 and a relatively fixed head it. The latter is internally threaded and threaded upon the threaded stern 'i5 of the piston head "i3, the stem 'i5 being bored longitudinally with a bore of square cross-section adapted to slidably receive a square shaft f6 carrying a hand wheel ll at its outer end and. a collar i8, these being located on opposite sides of the cylinder head i9. The piston head 'i4 has a piston rod 8l! which, as previously stated, is internally threaded. and. which passes outward through the opposite cylinder head 8i and is there connected to' a toothed rack 32. A pointer S3 is affixed to the side of the rack 82 and indicates the length of stroke of the rack 32 upon a scale 8f3 secured to the bed 54. As explained below in connection with the operation, the rotation of the hand wheel il and squared shaft 'i6 rotates the threaded stem 'l5 and thereby causes the piston head i3 to move toward or away from the piston head l2, thereby adjusting the length of the stroke of the piston rod and rack 82, as indicated by the pointer 83 upon the scale 3d.

The rack 82 meshes with a pinion 85 (Figures l, 2 and 3) mounted on a shaft Sii, the outer end of which is journaled in a bearing bracket 3l bolted to the bed 54, the inner end being journaled in the bed 54. The shaft t also carries a gear 38 which meshes with a pinion 39 upon the shaft 90. The shaft is journaled in the bore Si (Figure 3) of the hollow lower roll shaft 92 which is connected to the lower feeding roll 93, the opposite end of which is provided with the lower solid roll shaft 94. The inner end of the shaft 90 (Figure 3) is journaled in a bore 95 within a web 96 of the lower feeding roll 93.

Keyed to the inner end of the shaft 90 is the inner clutch member Sl of a unidirectional clutch Si! (Figures 3 and 6) the outer member 99 of which is keyed to the lower feeding roll 'd3 at the inner end of its hollow shaft 92.

The inner clutch member is provided at intervals around its periphery with arcuately tapered slots or recesses |00 in which are mounted clutch rollers l! urged toward the converging ends of the recesses It@ by coil springs 02, thereby urging the rollers IDI into clutching engagement with the internal cylindrical surface H33 of the external clutch member 99. By this construction, the rotation of the shaft 9d in a counterclockwise direction drives the outer clutch rneznber 99 but releases it upon rotation in a clockwise direction (Figure 6).

The lower roll shafts 52 and St are iournaled in aligned bores m4 and IE5 in the frame side members |06 and 01 respectively (Figure 3), these rising from the bed 5ftof the feeding device Il. Similarly, the hollow upper roll E93 is pro; vided with aligned end shafts H39 and lill journaled in aligned. bores Hi and H2 in the vertically reciprocable blocks H3. The blocks H3 are reciprocably mounted in elongated vertical guideways lili (Figure l). The blocks H3 are bolted at their upper ends to cross members l I5 (Figures l and 3) which at their opposite edges are provided with upstanding webs or flanges Ht (Figure 4) having inwardly extending bosses Ha bored to receive a pivot pin ill upon which is mounted the lower end of a link H8. The link H8 at its upper end is bored to receive a shaft H9 which at its opposite end has pinned to it a pair of eccentric bushings tzt. The eccentric bushings are journaled in aligned bores |2| in the opposite webs |22 of the frame cross member |23 which interconnects the frame side members |06 and |01 at the upper ends thereof (Figures 2 and 3). Mounted on the outer end of the shaft ||9 is a hand lever |24. Thus the cross members and |23 are of approximately U-shaped cross-section but face in opposite directions. Mounted between the outer ends of the cross members ||5 and |23 are compression coil springs (Figure 3), the upper ends of which are seated against the lower ends of adjusting screws |23. The screws |25 are threaded through threaded bores |21, carry loch nuts |28, and have squared upper ends for receiving a wrench.

Engaging the lower ends of the blocks ||3 are the upper ends of hydraulic plungers |29 which reciprocate in cylinder bores |30 formed in the frame side members |06 and |01 and facing upward. The lower ends of the cylinder bores |30 are provided with ports |3| to which are connected the inner ends of the pipe 50 leading from the lower hydraulic cylinder (Figure 1). By this means, the blocks ||3 and consequently the upper rolls |03 are raised and lowered in accordance with the motion of the platen I5. The pipe 50, of course, branches in order to extend to the cylinder bores |30 on opposite sides of the feeding device In order to provide a driving connection between the upper rolls |08 and lower rolls 93, regardless of their separation, the outer portions of the lower roll shafts 94 carry helical gears |32 (Figure 3) with 45 degree tooth angles. The gears |32 mesh with helical gears |33 (Figures l and 3) on the lower ends of Vertical shafts |34 journaled in brackets |35 bolted to the frame side members |01. Mounted on the upper ends of the shafts |34 are helical gears |35 meshing with helical gears |31 mounted on the outer end of the upper roll shafts ||0. In order to interconnect the two vertical shafts |34, a horizontal shaft |38 is provided at its opposite ends with helical gears |39 meshing with the helical gears |32. The horizontal shaft |38 is journaled at its opposite ends in brackets |40 bolted to the bed 54. In this manner, the rotation of the lower forward roll 93 is transmitted through its shaft 94 to the helical gear |32 and thence through the shafts |38 and |34 to the upper roll shafts ||0,

positively driving all four of the feed rolls 93 f and |08 respectively.

In order to prevent overriding of the feeding rolls 93 and |00, the outer ends of the lower roll shafts 94 are provided with brake drums |4| keyed thereto so as to be rotatable therewith. The brake drums |4| are engaged by the brake linings |42 attached to actuate brake bands |43 which encircle the brake drums |4| (Figures 3 and 5). Each brake band |43 is composed of upper and lower halves hinged together as at |44 and having forwardly projecting arms |45 at their free ends. The arms |45 are bored to receive a retaining pin |46, the upper end of which is threaded to receive a nut |41. Between the lnut |41 and one of the arms |45 is mounted a compression coil spring |48 which urges the arms |45 together, causing the brake band |43 to grip the brake drum |4| with a yielding grip, depending upon the adjustment of the nut |41 and the strength of the coil spring |48. In order to prevent the rotation of the brake band |43, the lower half thereof is provided with a downwardly-projecting arm |49 which is anchored in a slot |50 (Figures 3 and 5) formed in a bracket |5| bolted-to the bed 54. As a consequence, when the power is removed from the lower rolls 93 at the end of the feeding stroke, the yielding engagement of the brake linings |42 with the brake drums |4| brings the lower rolls 93 to an abrupt halt, thereby preventing over travel of the sheet material S. The latter is guided in its travel by grooved rollers |52 engaging its opposite edges and mounted on studs or pivot pins |53 carried by slides |54. The slides |54 have T-slots |55 which slidably engage T-section bars |55 bolted as at |51 to the bed 54. In order to lock the slides |54 in their positions of adjustment along the bars |56, each slide |54 is provided with a set screw |50 which engages the T-section bar |56.

Between the two sets of feeding rolls 93, |03 the feeding device is provided with lower and upper straightening rolls |59 and |63 respectively. The lower straightening rolls |59 are mounted on shafts |31 journaled at their opposite ends in the end members |52 inserted in corresponding cut-away portions |53 in the frame side members |06 and |01. The upper straightening rolls |30 are mounted on shafts |34 journaled at their opposite ends in blocks |35 which in turn are slidably mounted in vertical guideways |53 in the end members |52. Pinned or otherwise secured to the blocks |55 are raising and lowering screws |51 which are threaded into threaded bores |53 in vertical shafts |59 having their opposite ends journaled in bores |10 and |1| formed in an upper support |12 in the form of a block having a top member |13 mounted thereon. Each upper support |12 and end member |62 is bolted as at |14 to the side members |96 and |91 (Figure 1) whereas the top member |13 is bolted as at |15 to the upper member |12.

Mounted intermediate the ends of each shaft |59 is a worm gear |15. Each pair of worm gears |16 meshes with a worm |11 on a worm shaft |13 journaled in the upper members |12 and carrying a hand wheel |19 on one end thereof (Figure 2) The adjacent screws |51 on each side of the machine are oppositely threaded, one being a righthand thread and the other a left-hand thread. Thus, when the hand wheel |19 is turned to rotate the worm gears |15 in opposite directions, as shown by the arrows in the central portion of Figure 2, the screws |51 and blocks |55 will move upward or downward in the same direction. In this manner, the spacing cf the lower and upper straightening rolls |59 and |53 can be accurately adjusted. They are so adjusted as to grip the sheet material S with a sufiicientiy rm grasp to straighten out bent portions thereof but at the same time exert a sufficiently loose grip upon the sheet material S to permit the latter to be shifted slightly to and fro on the downstroke of the platen l5 while the upper feeding rolls |53 have been lifted by the hydraulic plungers |29 (Figure 3) and the pilot pin 22 enters the locating hole 24 to properly and accurately position the material which has already been fed to its approximate position by the feeding rolls 93 and |98.

In the operation of the invention, let it be assumed that the hand levers |24 and hand wheel accusa? fro along the T-section bars tt (Figure 2) so that they are properly' adusted to the width of the sheet S. Withv these adjustments completed, the hand levers |24 and hand: wheel |19 are operated in the opposite direction to lower the.- upper rolls |38. and |60 into contact with the sheet S resting on the lower rolls 53 and |59. The hand wheel |79A is carefully adjusted.V so that the upper straightening rolls |60. will perform their function without preventing longitudinal movement of the sheet S.

Let it be assumed that the platen l5,l is at` the middle of its stroke with the parts. of themechanism in the positions shown in. Figure 1, and that the sheet S has been moved forward until the pilot pin 22 is over thelocating hole* 24'. Let it also be assumed that the hand wheel' 1-1 has been adjusted so that the rack 2 attached to' the compound piston l2 will reciprocate a suici'ent distance, as shown on the scale Se, to advance the sheet material S the proper distance between strokes, ofthe platen f5, for the particular work pieces to be produced.

The operator now operates the startingV switch or starting mechanism of the machine lll to cause the platen la to descend in a working stroke. As the platen |51v descends, the upper cam follower 32 traverses thev upper straight portion of the cam groove 3e, hence nothing happens within the upper hydraulic cylinder 34'. during the downstroke of the platen l5. At the same time, however, the lower cam follower 32 and piston 33 are reciprocated to the right (Figure l.) by the downward motion of the oblique portion of the cam groove 3i in the lower cam plate 29, causing fluid within the lower cylinder 35 to be expelled under-pressure through the pipe 5d into the cylinder bores |38 (Figure 3). This pressure fluid, thus produced, acts against the hydraulic plungers |29 to raise them and the blocks ||3 against the downward force of the springs |25', thereby .raising both of the upper feeding rolls H33. When this occurs, the sheet S is free to move to or fro. As the platen |5` continues its downward stroke, the' pilot pin 22' enters the locating hole 2d in the sheet S (Figure l) and shifts the. sheet S to or fro until it is properly located, whereupon the continued downward travel of this platen l5 causes the punches I8 andv I9 to pass through the sheet S into the cavities 29 and 2|, punching out the holes 25 and 2S.

The platen. l5 is then reversed and moves upward. As it does so, the lower cam` follower 32 and lower piston 33: are subjectedV to the action of the oblique portion of the lower cam groove 3|, causing a suction in the lower cylinder 35 which withdraws fluid from the cylinder bores i3!) (Figure 3) by way of the pipe 5G and thus permits the upper feeding rolls l 93 to descend into engagement with the sheet materials, urged by the coil springs 25 and the force of; gravity. At the same time, the upper cam follower 32: and upper piston 33` are reciprocated to the right, expelling fluid under pressure from the cylinder 34 through the pipe t9 into the servo-motor. 5|, causing the piston 56 and valve rod 630i the valve 52 to shift to the left. When this occurs, iiuid is free to flow from the pressure; uid line 63 into the service line 65 and thence into the. right-hand end of the hydraulic motor 89 (Figure l) shifting the com-pound piston "l2, piston rod 33 and rack 32 to the left. This action rotates the pinion 85, shaft 86 and gear S8, consequently rotating the pinion B3, shaft 99 and inner clutch member 97 of the unidirectional clutch 98. This causes the inner clutch member 91 to; move in a counterclockwise direction (Figure 6) ,forcing the clutch rollers lillinto the smaller ends of the recesses mi! and jammingthe rollers ||l| tightly against the internalsurface |83 of the outer clutch member 9S; rotating the latter and consequently rotating the lower feed roll 93 in a counterclockwise direction.

The rotation of the lower feed roll 93 is transmitted-through the helical gears |32, |351, |33, |35, |31' and shafts |32. and |33 to the other lower feed roll 931 and to both upper feed rolls |68, causing the lower feed rolls 93 to rotate in a counterclockwise direction and the upper feed rolls |023 to rotate in a clockwise direction, advancing the strip of sheet material S the proper distance to present a fresh portion of stock to the action of'thepunches I8 and 9. When the platen I5A reaches the top of its stroke, it again reverses and makes' ai downward stroke in the manner previously described. During this downward stroke, and in every subsequent downward stroke, the upper feed rolls |68 are again raised by the action. of the pressure iiuid from the lower cylinders 35 passing through the pipes li into the cylinder bores l so that when the pilot pin 22 enters the next locating hole 2d, it can shift the sheet material S freely to enter the hole and cause the punches i8 and I9 to punch the next set of holes 25; 25 in the proper positions.

During the downstroke of the platen l5, the upper piston 33 is reciprocated to the left by the engagement' of the cam follower 32 with the oblique portion of the ea-m groove 30, causing the fluid to be withdrawn from the right-hand end of the servomotor 5|. The coil spring 51 then shifts the piston 56 and valve spool 6| of the control valve 52 to the right into'the position shown at the lower right-hand corner of Figure l. In this position, pressure fluid from the supply pipe 63 passes into the service pipe and thence into the left-hand end of the cylinder bore 7|, moving the compound piston 'l2' and rack 821 to the right into the position shown in Figure 1. This action rotates the shaft 90 in a clockwise direction, through the gear shaft 86 and gears 88 and 89. The lower roll shaft 92, and the lower feeding roll 93, however, remain stationary because of the action of the unidirectional clutch 98. The clockwise rotation of the inner clutch member 9T (Figure 6) moves the wider portion vof the recesses |00. toward the clutch rollers |0|,

releasing. their grip upon the internal surface |83 of the outerV clutch member 99, and hence causing the latter to slip relatively to the inner clutch member 51.

Duringr each forwardv stroke of each piston 33 ofthe cylinders 34 and 35, the excess fluid beyond that required for operating the respective plungers 56 and |29 is expelled through the port 4|', raising the ball relief valve members i4 and permitting the excess fluid to escape into the reservoir 3'1 through the ports lil and di). On the return stroke of the pistons 33, the additional fluid required to'fill the cylinder bore 34 enters from the reservoir 3l' through the port 39. The cylinders 311 and 35 are purposely made of larger volume than the servo-cylinder 55 and roll lifting cylinder |30 inV order to provide a quick response.

Thus, the feeding device automatically advarices. the strip of sheet material S the proper distance after each working stroke ofthe platen l5, then releases the grip of the feeding rolls upon the material S so as to permit the latter to be properly lined. up with the punches I8 and i9 by the pilot pin 22 entering the locating hole 24. The helical gear drive of the rearward lower feeding roll 93 and of both upper feeding rolls |08, causes these to rotate properly without any interruption or change in speed, regardless of the varying thicknesses of material `S being handled, since the centers of the meshing helical gears remain spaced at constant distances as the upper rolls |08 rise or fall. The present invention enables the sheet material for large stampings to be handled more conveniently than where a straight reciprocating feed is used, and the speed of feeding is increased and the feeding time shortened, since the feeding rolls operate in onlj,7 one direction. In the reverse direction, during the working or downward stroke of the platen I 5, the feeding rolls remain stationary due to the action of the unidirectional clutch 98. The freeing of the feeding rolls during the downward stroke of the platen l5 insures that the punches will punch their holes in the proper locations because the locating plunger or pilot pin 22 can freely enter the locating hole 24 and shift the sheet materials S in the proper direction to line it up accurately.

What I claim is:

1. A sheet stock feeding apparatus for sheet metal working machines with reciprocating platens comprising a frame, a pair of feeding rolls rotatably mounted one above the other on said frame, a fluid pressure piston and cylinder mounted on said frame, motion-converting mechanism drivingly connecting said piston to one of said rolls, a pressure, fluid control valve having an inlet adapted to be connected to a source of pressure fluid and an outlet connected to said cylinder, a servo-motor operably connected to said valve to shift said valve, and a fluid pressure pump drivingly connected to said platen of said machine and responsive to the motion thereof to generate and transmit pressure fluid to said servo-motor to shift said valve.

2. A sheet stock feeding apparatus for sheet metal working machines with reciprocating platens comprising a frame, a pair of feeding rolls rotatably mounted one above the other on said frame, a fluid pressure piston and cylinder mounted on said frame, motion-converting mechanism drivingly connecting said piston to one of said rolls, a pressure fluid control valve having an inlet adapted to be connected to a source of pressure fluid and an outlet connected to said cylinder, a servo-motor operably connected to said valve to shift said valve, a cam connected to said platen of said machine, and a fluid pressure pump operably engageable with said cam to generate and transmit pressure fluid to said servo-motor to shift said valve in response to the motion of said cam.

3. A sheet stock feeding apparatus for sheet metal working machines comprising a frame, a pair of vertically-spaced parallel horizontal feeding roll shafts rotatably mounted on said frame, a feeding roll mounted on each shaft, one of said roll shafts being adjustably movable toward and away from the other roll shaft, mechanism for rotating one of said roll shafts, a helical gear of 45" tooth angle connected to each roll shaft, a pair of helical gears of 45 tooth angles meshing with said roll-shaft-connected gears, said gears being fixedly secured against axial motion to their respective rolls and shafts, and an approximately vertical rotary shaft carrying and drivingly interconnecting said pair of helical gears.

4. A sheet stock feeding apparatus for sheet (iii metal working machines comprising a frame, two spaced pairs of vertically-spaced parallel upper and lower opposed feeding roll shafts rotatably mounted on said frame, a feeding roll mounted on each shaft, two of said roll shafts being adjustably movable in substantially vertical directions toward and away from the other two roll shafts, a helical gear of 45 tooth angles connected to each roll shaft, upper and lower helical gears meshing with each pair of roll-shaft-connected gears approximately vertical, said gears being ixedly secured against axial motion to their respective rolls and shafts, rotary shafts carrying and drivingly interconnecting the upper and lower helical gears, and mechanism drivingly interconnecting the lower helical gears.

5. A sheet stock feeding apparatus forsheet metal working machines comprising a frame, two spaced pairs of vertically-spaced parallel upper and lower opposed feeding roll shafts rotatably mounted on said frame, a feeding roll mounted on each shaft, two of said roll shafts being adjustably movable in substantially vertical directions toward and away from the other two roll shafts, a helical gear of 45 tooth angles connected to each roll shaft, upper and lower helical gears meshing with each pair of roll-connected gears, approximately vertical rotary shafts carrying and drivingly interconnecting the upper and lower helical gears, an additional pair of helical gears of 45 tooth angles meshing with the lower roll-shaft-connected helical gears, and an additional rotary shaft carrying and interconnecting said additional pair of gears, said gears being flxedly secured against axial motion to their respective rolls and shafts.

6. A sheet stock feeding apparatus for a sheet metal working machine having a reciprocable member, said apparatus comprising a frame, a pair of feeding rolls rotatably mounted on said frame, one of said rolls being adjustably movable toward and away from the other roll, a reciprocatory fluid pressure motor having a piston therein operatively connected to each end of said adjustably movable roll, a cam connected to said reciprocable member of said machine, and a fluid pressure pump hydraulically connected to said motor, said pump being operably engageable with said cam to generate and transmit pressure fluid to said motor to shift said roll in response to the motion of said cam resulting from the reciprocation of said reciprocable member.

7. A sheet stock feeding apparatus for sheet metal working machines comprising a frame, a pair of feeding rolls rotatably mounted on said frame, a fluid pressure piston and cylinder mounted on said frame, a rack connected to said piston, motion-converting mechanism drivingly connecting said rack to one of said rolls, one of said rolls being adjustably movable toward and away from the other roll, a pressure fluid control valve having an inlet adapted to be connected to a source of pressure fluid and an outlet connected to said. cylinder, a servo-motor operably connected to said valve to shift said valve, a reciprocatory fluid pressure motor connected to said adjustably movable roll, and fluid pressure pumping mechanism hydraulically connected to said motor and servo-motor and drivingly connected to a moving part of said machine, said pumping mechanism being ^responsive to `'the motion of said machine part in one direction to generate and transmit pressure fluid to said servo-motor to shift said valve, and responsive to the motion of said machine part in the opposite direction to generate Yand transmit pressure uid to .said motor to shift said motor-connected roll.

JOHN HALLER.

References Cited vin the 111e 0f this 'patent UNITED STATES PATENTS Number Name VDate McIver Mar. 27, 1866 Spohrer k Sept. 2, 1913 Desmond 1 Nov. 12, 1918 Terrey Apr. 17, 1923 Hoyoss Mar. 22, 1927 Meyer ..--1 June 14, 1927 Number 

